1. Field of the Invention
The present invention relates to a microwave oven, and more particularly to a microwave oven equipped with a microwave stirrer.
2. Description of the Prior Art
Generally, a microwave oven is a device for heating a foodstuff by radiating a microwave to a foodstuff. The microwave is generated by a magnetron. The magnetron generates a microwave having a frequency of about 2,450 MHz. When the microwave is radiated to the foodstuff placed in the microwave oven, the microwave stimulates molecules which constitute the foodstuff so that the molecules are rapidly vibrated, thereby generating a molecular frictional heat within the foodstuff. The microwave heats the foodstuff by using this frictional heat.
Generally, the microwave is generated by applying a high voltage to the magnetron. The high voltage is generated by a mutual induction between a first and second coils of a transformer installed at an inner bottom wall of a cabinet. By an antenna, the microwave is radiated into a chamber formed in the microwave oven.
FIG. 1 shows a conventional microwave oven 100. Microwave oven 100 comprises a cabinet 110 having an opening 105 at one side wall thereof. A door 150 is hinged at an edge portion of opening 105. Cabinet 110 is formed at an inner space thereof with a chamber 120 for receiving a foodstuff to be heated. A dish plate 140 for receiving a foodstuff thereon is mounted at a lower portion of chamber 120. Cabinet 110 is provided at an outer front surface thereof with a control panel 130 so as to adjust operating parameters such as a heating time according to a user's will.
Cabinet 11 is provided at one side wall thereof with a magnetron(not shown) for generating a microwave. An antenna(not shown) is provided at one edge portion of the magnetron, and radiates a microwave generated from the magnetron into the foodstuff in order to heat the foodstuff through a deep portion of the foodstuff.
FIG. 2 shows an inner structure of the conventional microwave oven 100. A separate space 615 is formed beneath chamber 120. A motor 630 is mounted at a lower portion of space 615. Motor 630 has a rotating shaft 635 upwardly extending to the lower portion of chamber 120 such that a rotating tray 650, which rotates above a bottom wall of chamber 120, is fixedly coupled to a free end of rotating shaft 635 by coupling 640. Consequently, when motor 630 is actuated, rotating tray 650 rotates together with rotating shaft 635. Rotating tray 650 supports dish plate 140 thereon. When dish plate 140 needs to be cleaned, dish plate 140 can be separated from rotating tray 650. For the stable rotation of rotating tray 650, a plurality of rollers 660 are mounted at a bottom wall of a circumferential portion of rotating tray 650 and are slidably supported on the bottom wall of chamber 120, thereby assisting rotating tray 650 to stably rotate.
As described above, microwave oven 100 is operated by actuating the magnetron and motor 630 in a state where a foodstuff is placed on a top surface of dish plate 140. By actuating motor 630, rotating shaft 635 begins rotation and consequently, dish plate 140 rotates together with rotating tray 650. The microwave generated by the magnetron is radiated to the foodstuff, thereby heating the foodstuff. However, in the conventional microwave oven 100, the microwave cannot be sufficiently reflected and dispersed in chamber 120 so that a dead zone, where the effect of the microwave is relatively weak, is formed in chamber 120, and as a result, the foodstuff is only partly heated. The above disadvantage is partly compensated by the rotation of dish plate 140, but it is not sufficiently solved.